000
AXPZ20 KNHC 062111
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2028 UTC Thu Jul 6 2017

Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2115 UTC.

...SPECIAL FEATURE...

A broad low pressure area in the monsoon trough was located near 
11.5N107.5W. It is moving slowly westward at about 10 kt. 
Scattered moderate isolated strong convection is observed within 
180-240 NM of the circulation center, roughly from 08N to 14N 
between 104W and 110W. Visible and infrared satellite imagery 
shows broad cyclonically curved convective bands around the 
circulation center in an area of low vertical shear, which is 
very favorable for further development. Environmental conditions 
are expected to remain favorable for the low to strengthen, and 
it could become a tropical cyclone within the next 48 hours. 
Please refer to the NHC Tropical Weather Outlook at 
hurricanes.gov for more information. A 1606 UTC ASCAT 
scatterometer pass indicated southwesterly 20-25 kt monsoonal 
flow within 180 NM in the SE semicircle of the low. This in 
conjunction with long period cross-equatorial swell has produced 
a band of 7 to 9 ft seas. 

...TROPICAL WAVES...

A tropical wave along 95W north of 11N is moving W at 10 to 15 
kt. Scattered moderate to strong convection is within 90 nm east 
of the wave axis. 

A tropical wave along 123W/124W from 13N to 22N moving west at 
10 kt has a weakening exposed low level center near 18.5N123W 
with minimal convection. The low is expected to dissipate within 
36 hours, with the parent tropical wave continuing westward, and
crossing 140W in about three days.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from Costa Rica near 09N83W to 12N100W
through the low pressure near 11.5N107.5W to 09N112W to 12N117W.
The monsoon trough then resumes from 12N125W to 09N140W.  
Scattered moderate isolated strong convection is observed 
elsewhere along the monsoon trough within 180 to 240 NM south of
the trough axis between 82W and 103W. Scattered moderate
convection was observed within 90 NM south of axis between 123W 
and 127W. 

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A ridge of high pressure extends across the waters west of Baja 
California. Light to moderate anticyclonic flow prevails west of 
the Baja California peninsula, moderate to fresh N winds in the 
Gulf of Tehuantepec, and light to gentle winds over the Gulf of 
California. Seas are 4-6 ft in the open waters west of Mexico, 
with 1-2 ft seas in the Gulf of California. Nocturnal winds will 
pulse to a max of 20 kt each night in the Gulf of Tehuantepec, 
then diminish during the day. Little change expected elsewhere.
    
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR... 

Moderate to locally fresh nocturnal winds are expected in the 
Gulf of Papagayo for the remainder of this week. Gentle to 
moderate southerly winds are expected south of the monsoon trough
as well. Long period cross-equatorial S to SW swell and seas to 
8-9 ft W of Colombia and Ecuador will subside Friday into the
weekend. 

REMAINDER OF THE AREA...
  
See special feature section for more information on the low 
centered near 11.5N107.5W. Outside the influence of this area, 
gentle to moderate trade winds will prevail north of the monsoon 
trough, while moderate to fresh southerly winds will be south of 
the trough axis. Seas will be generally 5-7 ft. These general 
conditions are expected to prevail through the rest of the week.

$$
Cobb